//
// GamePaddle class
// part of the set of documents known as Java no sugar.
// Copyright (c) 1996 Sunil Gupta, sunil@magnetic.demon.co.uk
// placed into the public domain by the author
//
import java.awt.*;
public class GamePaddle extends Canvas
{
//##################################################################
//
//##################################################################
public static final int NONE_PRESSED = 0;
public static final int PRESSED_NORTH = 1;
public static final int PRESSED_EAST = 2;
public static final int PRESSED_SOUTH = 4;
public static final int PRESSED_WEST = 8;
private static final double ROOT2 = 1.414213562373;
private static final double FUDGEFACTOR = 1.66666;
public int CLICK_INTERVAL = 100; //milliseconds
int button_state = NONE_PRESSED;
long button_down_time;
//##################################################################
//
//##################################################################
public GamePaddle()
{
}
public int direction()
{
return(button_state);
}
//******************************************************************
// initial size must be set in addNotify, not in constructor or
// tharr be null pointers
public void addNotify()
{
super.addNotify();
resize(this.preferredSize());
}
//******************************************************************
public void paint (Graphics g)
{
Dimension size;
int x, y, text_width, text_height, oval_width, oval_height;
Color colour;
//--------------------------------------------------------------
size = size();
//------draw button shape ---
g.setColor( getBackground() );
g.fillRect(0,0,size.width, size.height);
switch(button_state)
{
case PRESSED_NORTH:
paint_pressed_north(g);
break;
case PRESSED_EAST:
paint_pressed_east(g);
break;
case PRESSED_SOUTH:
paint_pressed_south(g);
break;
case PRESSED_WEST:
paint_pressed_west(g);
break;
default:
paint_pressed_none(g);
}
}
//******************************************************************
private Polygon north_polygon()
{
Dimension size;
Polygon polygon;
int h1,h2,h3;
int w1,w2,w3;
size=CellSize();
h1 = size.height-1;
h2 = h1+size.height;
h3 = h2+size.height;
w1 = size.width-1;
w2 = w1+size.width;
w3 = w2+size.width;
polygon = new Polygon();
polygon.addPoint( w1 +4, 0);
polygon.addPoint( w2 -4, 0);
polygon.addPoint( w2 -2, h1);
polygon.addPoint( w3 -2, h1);
polygon.addPoint( w3, h2);
polygon.addPoint( w2, h2);
polygon.addPoint( w2 +2, h3);
polygon.addPoint( w1 -2, h3);
polygon.addPoint( w1, h2);
polygon.addPoint( 0, h2);
polygon.addPoint( 2, h1);
polygon.addPoint( w1+2, h1);
polygon.addPoint( w1+4, 0);
return(polygon);
}
//******************************************************************
private Polygon west_polygon()
{
Dimension size;
Polygon polygon;
int h1,h2,h3;
int w1,w2,w3;
size=CellSize();
h1 = size.height-1;
h2 = h1+size.height;
h3 = h2+size.height;
w1 = size.width-1;
w2 = w1+size.width;
w3 = w2+size.width;
polygon = new Polygon();
polygon.addPoint( w1 , 2);
polygon.addPoint( w2, 0);
polygon.addPoint( w2, h1);
polygon.addPoint( w3, h1 -2);
polygon.addPoint( w3, h2 +2);
polygon.addPoint( w2, h2);
polygon.addPoint( w2, h3);
polygon.addPoint( w1, h3-2);
polygon.addPoint( w1, h2-2);
polygon.addPoint( 0, h2-4);
polygon.addPoint( 0, h1+4);
polygon.addPoint( w1, h1 +2);
polygon.addPoint( w1, 2);
return(polygon);
}
//******************************************************************
private void paint_pressed_north(Graphics g)
{
paint_button_face(g,north_polygon());
}
//******************************************************************
private void paint_pressed_east(Graphics g)
{
Polygon west_polygon, east_polygon;
Dimension size;
int npoints,point, y;
west_polygon = west_polygon();
size=size();
npoints = west_polygon.npoints;
// --------------------flip polygon------------------------
for (point=0; point < npoints; point++)
west_polygon.xpoints[point] = size.width -west_polygon.xpoints[point];
//-------now anticlockwise, so reverse points--------------
east_polygon = new Polygon();
for (point=npoints-1; point >=0; point--)
east_polygon.addPoint( west_polygon.xpoints[point], west_polygon.ypoints[point]);
paint_button_face(g, east_polygon);
}
//******************************************************************
private void paint_pressed_south(Graphics g)
{
Polygon north_polygon, south_polygon;
Dimension size;
int npoints,point, y;
north_polygon = north_polygon();
size=size();
npoints = north_polygon.npoints;
// --------------------flip polygon------------------------
for (point=0; point < npoints; point++)
north_polygon.ypoints[point] = size.height -north_polygon.ypoints[point];
//-------now anticlockwise, so reverse points--------------
south_polygon = new Polygon();
for (point=npoints-1; point >=0; point--)
south_polygon.addPoint( north_polygon.xpoints[point], north_polygon.ypoints[point]);
paint_button_face(g, south_polygon);
}
//******************************************************************
private void paint_pressed_west(Graphics g)
{
paint_button_face(g, west_polygon());
}
//******************************************************************
private void paint_pressed_none(Graphics g)
{
Dimension size;
Polygon polygon;
int h1,h2,h3;
int w1,w2,w3;
size=CellSize();
h1 = size.height;
h2 = h1+size.height;
h3 = h2+size.height;
w1 = size.width;
w2 = w1+size.width;
w3 = w2+size.width;
polygon = new Polygon();
polygon.addPoint( w1, 0);
polygon.addPoint( w2, 0);
polygon.addPoint( w2, h1);
polygon.addPoint( w3, h1);
polygon.addPoint( w3, h2);
polygon.addPoint( w2, h2);
polygon.addPoint( w2, h3);
polygon.addPoint( w1, h3);
polygon.addPoint( w1, h2);
polygon.addPoint( 0, h2);
polygon.addPoint( 0, h1);
polygon.addPoint( w1, h1);
polygon.addPoint( w1, 0);
paint_button_face(g,polygon);
}
//******************************************************************
private void paint_button_face(Graphics g, Polygon p)
{
int point;
int x1,y1,x2,y2;
int dx1,dy1,dx2,dy2;
boolean first_point;
//---draw the basic button shape-------------------
g.setColor( Color.lightGray);
g.fillPolygon(p);
//---draw the dark grey shading on downward faces---
g.setColor( Color.gray);
first_point = true;
x1 = y1 = 0;
for ( point =0; point < p.npoints; point++)
{
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
x2 = p.xpoints[point];
y2 = p.ypoints[point];
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
if ((! first_point) & ( y2 > y1))
{
if (x2 <= x1) //dark bit is above line
{
dx1 = -1; dy1 = 0;
dx2 = 0; dy2 = 1;
}
else if (x2 == x1)
{
dx1 = -1; dy1 = 0;
dx2 = -1; dy2 = 0;
}
else
{
dx1 = 0; dy1 = -1;
dx2 = -1; dy2 = 0;
}
g.drawLine(x1+dx1, y1+dy1, x2+dx2 , y2+dy2);
}
else
first_point = false;
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
x1 = x2;
y1 = y2;
}
//---draw the black edges of downward faces---
g.setColor( Color.black);
first_point = true;
x1 = y1 = 0;
for ( point =0; point < p.npoints; point++)
{
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
x2 = p.xpoints[point];
y2 = p.ypoints[point];
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
if ((! first_point) && (y2 > y1))
{
g.drawLine(x1,y1,x2,y2);
}
else
first_point = false;
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
x1 = x2;
y1 = y2;
}
//---draw the highlights on the upward faces--------
g.setColor( Color.white);
first_point = true;
x1 = y1 = 0;
for ( point =0; point < p.npoints; point++)
{
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
x2 = p.xpoints[point];
y2 = p.ypoints[point];
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
if ((! first_point) && (y2 <= y1))
{
g.drawLine(x1,y1,x2,y2);
}
else
first_point = false;
//- - - - - - - - - - - - - - - - - - - - - - - - - - - -
x1 = x2;
y1 = y2;
}
}
//******************************************************************
private Dimension CellSize()
{
Dimension size;
int cell_width, cell_height;
size = size();
cell_width = size.width / 3;
cell_height = size.width / 3;
return new Dimension(cell_width, cell_height);
}
//******************************************************************
public Dimension minimumSize()
{
return ( new Dimension (100,100));
}
//******************************************************************
public Dimension preferredSize()
{
return minimumSize();
}
//******************************************************************
public boolean handleEvent(Event e)
{
long time_diff;
int cell_number;
Dimension cell_size;
switch (e.id)
{
case Event.MOUSE_DOWN:
button_down_time = System.currentTimeMillis();
cell_size = CellSize();
cell_number = 3 *(e.y / cell_size.height) + (e.x / cell_size.width);
switch (cell_number)
{
case 1:
button_state = PRESSED_NORTH;
break;
case 3:
button_state = PRESSED_WEST;
break;
case 5:
button_state = PRESSED_EAST;
break;
case 7:
button_state = PRESSED_SOUTH;
break;
default:
button_state = NONE_PRESSED;
break;
}
if (button_state != NONE_PRESSED)
repaint();
return true;
case Event.MOUSE_UP:
if (button_state != NONE_PRESSED)
{
time_diff = System.currentTimeMillis() - button_down_time;
if (time_diff <= CLICK_INTERVAL)
postEvent(new Event(this,Event.ACTION_EVENT,this));
button_state = NONE_PRESSED;
repaint();
}
return true;
default:
return super.handleEvent(e);
}
}
}
.